Projection printing machine



Filed D60. 18, 1929 7 Sheets-Sheet l INVENTOR w r m 0 E M N w QM T ELMF w Mi Z 0 l fl W 1, 1. n1 5 7, A @A L a 6 n m w 0 Maw m 5 y 1932- J. BURKHARDT 1,859,022

PROJECTION PRINTING MACHINE Filed Dec. 18, 1929 7 Sheets-Sheet 3 INVENTOR B I, J4 kaf/ ar/r/M/W/ V6 gg W 4 TT OQI Y5 y 1932- .1. BURKHARDT 1,859,022

PROJECTION PRINTING MACHINE FiledDec. 18, 1929 7 Sheets-Sheet 4 A TTORNEY 5 y 1932. J. BURKHARDT' PROJECTION PRINTING MACHINE Filed Dec. 18. 1929 7 Sheets-Sheet 5 May 17, 193 J. BURKHAR'DT PROJECTION PRINTING MACH INE Filed Dec. 18, 1.929 7 Sheets-5heet 6 5 HDQDQQQQQQQQU VQQQQDQQQQQQD NE YS May 17, 1932- J. BURKIHARDT PROJECTION PRINTING MACHINE Filed Dec. 18, 1929 7 Sheets-Sheet 7 Patented May 17, 1932 UNITED STATES PATENT OFFICE JAKOB BURKHARDT, OF DETROIT, MICHIGAN, ASSIGNOR TO THIRD DIMENSION PICTURES, INQ, OF NEW YORK, N. Y.

PROJECTION PRINTING MACHINE Application filed December 18, 1929. Serial No. 414,935.

The main objects of this invention are: housing being removed and the light direct- First, to provide a projection printer for ing prism being shown by dotted lines. moving picture films which is largely auto- Fig. 5 is an enlarged detail section on a matic in eration and may be readily adline corresponding to line 5 of Fig.3show- 5 justed to t e particular work and also ading details of the film feed mechanism, this usted for reducing film or printing in minmechanism being the same for both the posiiaturo. tive and negative film and this figure show- Second, to provide a printing machine for ing the feed mechanism for the positive film. printing films having a foreground and a Fig. 6 is a fragmentary view mainly in sec- 1 background picture in a single picture space tion on a line corresponding to line 6-6 of or frame of a film and also printing a mask Figs. 3 and 5 illustrating details of the film of one of the pictures upon the other, an express re Shoe. ample of such film being illustrated in my Fig. 7 is a detail section on a line correapplication for Letters Patent filed April 22, sponding to line 7-7 of Figs. 3 and 5 showing .5 1929, Serial No. 357,146. further details of the centering and support- 55 Third, to provide a machine having these g o the film. advantages which may also be employed for g- 8 IS a fragmentary inverted view of printing standard film, that is, film having the negative feed mechanism illustrating the frames or. picture spaces of standard dimen- I e1at10I1 0f e Shut er thereto and the adsions, in combination with a sound record. J l fr l g OI masking member. 70

Objects pertaining to details and economies g- 9 s a fragm ntary plan view of the of my invention will definitely appear from parts Of the negative feed mechanism, particthe description to follow. The invention is ularly the film guide and framing means.

defined in th claims, Fig. 10 is a top perspective view of the A machine which embodies the features of p s film mask- 75 my invention is clearly illustrated in the ac- Fig 11 is a plan view of the mask adapted companying drawings, in which: for printing a standard film.

Fig. 1 is a front elevation of my improved Fig. 12 is a perspective view of a removprinting machine, the positive film and its able mask which is removed to adapt the supporting and driving means being shown a k to a Standard film. w and the negative film being omitted. For Fig. 13 is a conventional fragmentary tions of the telescopic light tube between View f the positive film, the relation of the the lamp housing and the focusing lens are P l e g t onally shown. indicated by dotted lines in order to better 14 a fragmentary new of h P di l th -t tive film with a sound record conventionally 5 Fig. 2 is a fragmentary side elevation with mdlfiaifid thereon the negative film in position and the positive 15 1s a fragmentary elevatlon Show in the machine adjusted for the printin of 2 :2223? Its dnvmg and Wmdmg mechamsm a standard film, the positive and negative g 3 isra horizontal section on line films in this adjustment being in the same no of Fig. 2 showing details of the positive film Vertlcal plane" Referring to the drawings the machine feed mechanism, its guide means and the propel. is mounted upon a pedstal or base L mask W1th the mask ll i i0 punt This pedestal carries standardsQand 3. The leftqhandplcture onthe P W table 4 is mounted on these standards for 95 4 1s a fFagmentaFy p fi y vertical adjustment and is provided with horizontal section on a line corresponding to lid 5 carrying i i 6 ti ith th line44 of F lgs. 1 and 2 Showi g d l f racks 7 on the standards. These pinions are the negative feed and winding mechanism, mounted on a shaft 8 having a worm 9 therethe guide means andmask, the top of the lamp on coacting with the driving worm 10 pmwe vided with a crank 11 so that by turning the crank 11 the table may be moved up and down. The worm driving connection constitutes means for holding the parts in adjusted position, but in order to prevent accidental movement of these parts I further provide set screws 12.

The pedestal is provided with a fixed bed 13 on'which the positive film driving mechanism is mounted. The negative film driving mechanism is mounted on the table 4.

The lamp housing 14 is carried by the adjustable table 4.'

The negative film is shown at 15, the spool 16 being mounted on'an arm 17 projecting from the post or standard 2. The rewind spool 18 is provided with a driving spindle 19 which is connected to the main driving shaft 20 by means of a. verticallly disposed transmission shaft 21 having a beveled gear 22 at its lower end meshing with a gear 23 on thedriving shaft 20 and a gear 24 at its upper end meshing with a beveled gear 25 on the shaft 26, which, in turn, has a beveled gear 27, indicated by dotted lines in Fig. 2, meshing with a gear 28 on the spindle 19.

The feed mechanisms for both the positive film and the negative film are driven from the shaft 21 which is provided with beveled gears 29 and 30 meshing with the beveled gears 31 and 32, respectively, on the shafts 33 and 34 which are provided with universal and telescoping joints or couplings permitting adjustment of the parts.

The negative film is threaded through a projector 35 which in the main is of standard construction and provided with means for feeding the negative film with a step by step movement driven by the shaft 34 so that it is driven in synchronism with the positive film driven by the shaft 33.

I have not detailed the lens and the feed mechanism of the negative film as this is substantially the same as that of the positive film which is detailed and will be described later.

I have, however, provided a telescoping light tube made up of parts 36 and 37 between the projector proper and the reflecting prism housing 38. The-section 37 may be telescoped with the section 36 to permit threading of the negative through the projector. The section 37 is merely lifted up on the section 36 to afford access to the parts below.

I provide a special shutter 39 for the projector best shown in Fig. 8. This shutter is mounted on a vertical spindle 40 and is provided with an adjustable segment 41 having segmental slots 42 therein to receive the screws 43. The, shutter is operatively associated with the picture frame member 44 having a rack 45 projecting therefrom into coacting relation with the toothed spindle 46 which projects from the housing and is provided with a knurled finger piece 47. This permits adjustment of the frame member 44 to properly position the same relative to the positive film.

The feed fingers for the negative film are indicated at 48.

The shutter is connected to the shaft 49 having a fly wheel 50 thereon by means of the shaft 51 and the gears 52 and 53, see Fig. 8. The shaft 49 projects from the projector housing and is provided wit a worm gear 54 coacting with a worm 50 on the shaft 34.

The feed fingers are driven by the crank disk 56 on the inner end of the shaft 49. The cam for controlling the movement of the feed fingers is shown at 57. With this arrangement an exact timing of the shutter may be easily had.

The positive film 58 is provided with spools 59 and the rewind sppols 60. This film is fed by means of the driving sprockets 61 and the take-up sprockets 62. The shafts 63 and 64 of these sprockets are connected by a sprocket chain 65 so that they are driven in timed relation.

The shaft 63 is provided with a beveled gear 66 meshing with a beveled gear 67 on the transmission shaft 68 which is in turn connected to the shaft 33 by means of the beveled gears 69, see Fig. 3. Guide rollers 70 and 71 coact with the sprockets in holding the film thereto. The rollers 71 are grooved and mounted on a swinging arm 72 which is swung or urged toward the sprockets by means of the springs 73.

The machine, as stated, is especially designed for use in printin miniature pictures, such as foreground and background pictures in side by side relation in a single frame or picture space of the film. Toaccomplish this it is necessary to provide an adjustable masking means and means for positively feeding and guiding the film.

The printing box comprises a chambered base member 74 which is secured in position in the frame 75 by means of the screws 76, see Figs. 3 and 5. The feed fingers 77 are housed within this base member and mounted on the crank 78 and supported in the cam slot 79 so that as the crank is rotated the fingers are swung through the slots 80 in the base member into engagement with the perforation of the film, see Fig. 6v in which the fingers are in feeding position.

The film is guided by the members 81 mounted on the base member 74 and rabbeted at 82 to receive the edges of the film. At the printing point the film is held firmly against the rear guide member by means of a lateral pressure shoe 83 which is slidably mounted in the front guide'member for lateral movement therein and is yieldingly held inward by means of the spring 84. An adjustable support is provided to vary the tension of this spring, see Figs. 3 and 7.

To firmly support the film at the feeding point I provide a pair of channel-shaped press shoes 86 which enga e the film at op- )osite sides of the feed per orations as shown in Fig. 6. These press shoes are yieldingly urged upon the fi'lm by means of the thrust plate 87 which is engaged by the spring 88 arranged on the vertical pin 89 at the inner side of the yoke 90.

The press shoes 86 are arranged in slots 91 in the plate 92 which is pivoted at 93 on the ears 94 so that it may be swung out of the way for threading the film. This plate is held in its operative position by means of the latch 95.

The plate 92 is the mask-carrying plate and is provided with a rabbeted seat 96 for the mask 97 which has beads or ribs 98 on its lower edge in engagement with the film. The mask 97 has an aperture 99 of the full dimensions of the film frame.

To adapt it for miniatures the mask is provided with a removable member 100 adapted to fit into the recess 101 in the top of the maskand having a tongue-like projection 102 complementing the walls of the mask, see Figs. 7, 10, 11 and 12.

This mask may be reversed in the mask holder or plate for printing either side of the film, as for printing a background at one side and a foreground at the other, the film being run through the machine twice. That is, the backgrounds are printed at one operation and the foregrounds in a succeeding operation. a

The background negative is preferably prepared with amask of the foreground so that the printed film is adapted for producing third dimensional picture effects when projected, as described in my above mentioned application for patent.

The mask is yieldingly clamped in position by means of the clamping frame 103 which is pivoted at 104 so that it may be swung out of the way in threading the film. The swinging end of the frame is engaged by the yoke 90 on the pin 89.

The yoke is held under tension by means of the coiled spring 105 on the pin. The studs 106 position the outer end of the clamping frame and also the yoke.

This clamping frame 103 carries the light tube 107 which is adjustably mounted on the frame by means of screws 108 engaging the slots 109, the purpose being to permit centering the tube relative to the mask, that is, to permit adjustment of the tube when the mask is changed from printing a. picture on one side of the film to the other side.

A finder lens 110 is provided which is arranged in a branch 111 of the light tube 107.

65 A telescopic connection 112 is provided for connecting the light tube 107 with the focusing lens tube or projector tube 113.

In reversing the mask it is necessary to adjust it in order to maintain its proper centered relation to the projecting lens. This is accomplished by adjusting the base member 74 which is slidable within the frame 75, the spacer bar 114 being of such thickness as to center the mask for the purpose described when it is in its holder. This bar is supported in its adjusted position by means of screws 115. see Fig. 3.

The screws 76 are not adjusted to clamping engagement with the base member but are provided for the proper positioning thereof, allowing it to be shifted for the purpose stated.

In the embodiment illustrated the rewinding spool spindle 19 is driven through a pulley 116 having a friction connection with the spindle indicated at 117. This pulley is driv en through the belt 118 from a pulley 119 on the shaft 33. i

The feed mechanism through its shaft 49 and the worm gear 54 is connected by the shaft 120 and the worm gears 121 and 122 to the shaft 33. The parts are all thus connected to be driven in timed relation or in synchronism.

In the embodiment illustrated the motor 123 is mounted within the pedestal 1 and is connected by the belt 124 to a pulley 125 on the shaft 20 the structure thus comprising a complete unit.

My improved projection printing machine is adapted for printing miniature pictures side by side on a film in associated pairs, or it may be employed for printing films having pictures of standard size or frames.

I have illustrated and described my improvements inan embodiment which I have found very practical. I have not attempted to illustrate or describe certain adaptations or modifications which I contemplate as it is believed that this disclosure will enable those skilled in the art to embody or adapt the same as may be desired.

Having thus described my invention what I claim as new and desire to secure by Letters Patent is:

.1. In a printing machine, the combination with a projecting mechanism, of a positive film mechanism comprising a base member mounted for adjustment transversely of the path of the film and having feed finger slots therein, feed fingers and actuating means therefor, film guide members rabbeted to re.- ceive the edges of the film mounted on said base member in opposed relation, a spring pressed thrust member on one of said guide members engaging an edge of the film at the printing point, channeled pressure shoes disposed to engage the film in operative relation to Said feed fingers, a mask holder pivotally mounted at one side of the path of the film and slotted to receive said pressure shoes and having a mask opening therein with surrounding mask seat, a mask reversibly arranged in sald seat and having a recess 1n its face, a mask reducing member removably mounted in. said recess, a mask clamping frame pivotally mounted at one side of said mask holder so that it may be swung out of the pat-h thereof permitting the opening of the mask holder, a post on said mask holder having a clamping yoke mounted thereon, said clamping plate being provided with pins engaging the ends of said yoke, a pressure shoe thrustplate mounted on said post to engage said pressure shoes, a spring arranged between said thrust plate and yoke, a pressure spring for said oke arrarliiged on said post at the outer side of the yo e.

2. In a printing machine, the combination with a projecting mechanism, of a positive film mechanism comprising a base member mounted for adjustment transversely of the path of the film and having feed finger slots therein, feed fingers and actuating means therefor, film guide members rabbeted to receive the edges of the film mounted on said base member in opposed relation, a spring pressed thrust member on one of said guide members engaging an edge of the film at the printing point, channeled pressure shoes disposed to engage the film in operative relation to said feed fingers, a mask holder pivotally mounted at one side of the path of the film and slotted to receive said pressure shoes and having a mask opening therein with surrounding mask seat, a mask reversibly arranged in said seat and having a recess in its .facc, a mask reducing member pivotally mounted in said recess, and a mask clamping frame pivotally mounted at one side of said mask holder so that it may be swung out of the path thereof permitting the opening of the mask holder.

3. In aprinting machine, the combination with a projecting mechanism, of a positive film mechanism comprising a base member mounted for adjustment transversely of the path of the film and having feed finger slots therein, feed fingers and actuating means therefor, film guide members rabbeted to receive the edges of the film mounted on said base member in opposed relation, a spring pressed thrust member on one of' said guide members engaging an edge of the film at the printing point, channeled pressure shoes disposed to engage the film in operative relation to said feed fingers, a mask holder pivotally mounted at one side of the path of the film and slotted to receive said pressure shoes and having a mask opening therein with surrounding mask seat, a mask reversibly arranged in said seat and having a recess in its face, a mask reducing member pivotally mounted in said recess, a mask clamping frame pivotally mounted at one side of said mask holder so that it may be swung out of the path thereof permitting the opening of the mask holder, and a light tube mounted on said clamping member for adjustment transversely of the path of the film.

4. In a printing machine, the combination with a projecting mechanism, of a positive film mechanism comprising a chambered base member mounted for adjustment transverse- 1y of the path of the film, the top of said base member having feed finger slots therein, feed fingers and actuating means therefor mounted within said base member, film guide members rabbeted to receive the edges of the film mounted on said base member in opposed relation, a spring pressed thrust member on one of said guide members engaging an edge of the film at the printing point, channeled pressure shoes disposed to engage the film in operative relation to said feed fingers, a mask holder pivotally mounted at one side of the path of the film and slotted to receive said pressure shoes and having a mask opening therein with surrounding mask seat, a mask reversibly arranged in said seat and having a recess in its face, a mask reducing member removably mounted in said recess, and a mask clamping frame pivotally mounted at one side of said mask holder so that it may be swung out of the path thereof permitting the opening of the mask holder.

5. In a printing machine, the combination with a projecting mechanism, of a positlve film mechanism comprising a base member having feed finger slots therein, feed fingers and actuating means therefor mounted within said base member, pressure shoes disposed to engage the film in operative relation to said feed fingers, a mask holder pivotally mounted at one side of the path of the film and slotted to receive said pressure shoes and having a mask opening therein with surrounding mask seat, a mask reversibly arranged in said seat and having a recessin its face, a mask reducing member removably mounted in said recess, a mask clamping frame pivotally mounted at one side of said mask holder so that it may be swung out of the path thereof permitting the opening of the mask holder, a post on said mask holder having a clamping yoke mounted thereon, said clamping plate being provided with pins engaging the ends of said yoke, a pressure shoe thrust plate mounted on said post to engage said pressure shoes, a spring arranged between said thrust plate and yoke, and a pressure spring for said yoke arranged on said post at the outer side of the yoke.

6. In a printing machine, the combination with a projecting mechanism, of a positive film mechanism comprising a base member having feed finger slots therein, feed fingers and actuating means therefor mounted within said base member, pressure shoes disposed to engage the film in operative relation to said feed fingers, a mask holder pivotally mounted at one side of the path of the film and slotted to receive said pressure shoes and having a mask opening therein with surrounding mask seat, a mask reversibly arranged in said seat and having a recess in its face, a mask reducing member pivotally mounted in said recess, and a mask clamping frame pivotally mounted at one side of said mask holder so that it may be swung out of the path thereof permitting the opening of the mask holder.

7. In a printing machine, the combination with a projecting mechanism, of a positive film mechanism comprisinga base member mounted for adjustment transversely of the path of the film having feed finger slots therein, feed fingers and actuating means therefor mounted within said base member,

pressure shoes disposed to engage the film in operative relation to said feed fingers, a

mask holder pivotally mounted at one side of the path of the film and slotted to receive said pressure shoes and having a mask opening therein with surrounding mask seat, a mask reversibly arranged in said seat and having a recess in its face, a mask reducing member removably mounted in said recess, a mask clamping frame pivotally mounted at one side of said mask holder so that, it may be swung out of the path thereof permitting the opening of the mask holder, and a light tube mounted on said clamping member for adjustment transversely of the path of the film.

8. In a printing machine, the combination with a projecting mechanism, of a positive film mechanism comprising a base member mounted for adjustmenttransversely of the path of the film, film guide members rabbeted to receive the edges of the film mounted on said base member in opposed relation, one of said guide members having a spring pressed element engaging the edge of the film at the printing point, amask holder having a mask opening therein, a mask reversibly arranged in said mask opening and having a, recess in its face, a mask reducing member removably mounted in said recess, a mask clamping member adapted to engage said mask and its said reducing member, a light tube mounted on said-mask clamping member for adjustment relative to the mask, and means for feeding the film step by step.

9. In a printing machine, the combination with a projecting mechanism, of a positive film mechanism comprising film guide members rabbeted to receive the edges of the film mounted on said base member in opposed relation, one of said guide members having a spring pressed element engaging the edge of the film at the printing point, a mask holder having a mask opening therein, a mask reversibly arranged in said mask opening and having a recess in its face, a mask reducing member removably mounted in said recess, a mask clamping member adapted to engage said mask and its said reducing member, a light tube mounted on said mask clamping member for adjustment relative to the mask, and means for feeding the film step by step.

10. In a printing machine, the combination with a projecting mechanism, of a positive film mechanism comprising a base member mounted for adjustment transversely of the path of the film, film guide members rabbeted to receive the edges of the film mounted on said base member in opposed relation, one of said guide members having a spring pressed element engaging the edge of the film at the printing point, a mask holder having a mask opening therein, a mask reversibly arranged in said mask opening and having a recess in its face, a mask reducing member removably mounted in said recess, a mask clamping member adapted to engage said mask and its said reducing member, and means for feeding the film step by step.

11. In a printing machine, the combination with a projecting mechanism, of a positive film mechanism comprising film guide members rabbeted to receive the edges of the film mounted on said base member in opposed relation, one of said guide members having a spring pressed element engaging the edge of the film at the printing point, a mask holder having a mask opening therein, a mask reversibly arranged in said mask opening and having a recess in its face, a mask reducing member removably mounted in said recess, a mask clamping member adapted to engage said mask and its said reducing member, and means for feeding the film step by step.

12. In a printing machine, the combination with a. projecting mechanism, of a positive film mechanism comprising a base member mounted for adjustment transversely of the path of the film. a mask holder having a mask opening therein, a mask reversibly arranged in said mask opening and having a recess in its face, a mask reducing member removably mounted in said recess, a mask clamping member adapted to engage said mask and its said reducing member, a light tube mounted on said mask clamping member for adjustment relative to the mask, and means for feeding the film step by step.

13. In a printing machine, the combination with a projecting mechanism, of a positive film mechanism comprising a mask holder having a mask opening therein, a mask reversibly arranged in said mask opening and having a recess in its face, a mask reducing member removably mounted in said recess, a mask clamping member adapted to engage said mask and its said reducing member, a light tube mounted on said mask clamping member for adjustment relative to the mask, and means for feeding the film step by step.

14. In a printing machine, the combination with a projecting mechanism, of a positive film mechanism comprising a base member mounted for adjustment transversely of the path of the film, a mask holder having a mask opening therein, a mask reversibly arranged in said mask opening and having a recess in its face, a mask reducing member removably mounted in said recess, a mask clamping member adapted to engage said mask and its said reducing member, and means for feeding the film step by step.

15. In a printing machine, the combination with a projecting mechanism, of a positive film mechanism comprising a mask holder having a mask opening therein, a mask reversibly arranged in said mask opening and having a recess in its face, a mask reducing member removably mounted in said recess, a mask clamping member adapted to engage said mask and its said reducing member, and means for feeding the film step by step. 1

16. In a printing machine, the combination of a projecting mechanism, a positive film mechanism comprising film guiding members coacting with the edges of the film and including a yieldingly supported element engaging the film at the printing point, a reversibly supported mask provided with a reducing member, and a light tube operative 1y associated with the projecting mechanism and mounted for adjustment transversely of the path of the film.

17.. In a printing machine, the combination of a projecting mechanism, a positive film mechanism comprising a reversibly supported mask for the film provided with a reducing member, and a light tube operatively associated with the projecting mechanism and mounted for adjustment transversely of the path of the film.

18. In a printing machine, the combination of a projecting mechanism, a positive film mechanism comprising film guiding members coacting with the edges of the film and including a yieldingly supported element engaging the film at the printing point, and a reversibly supported mask provided with a reducing member disposed adjacent the film at the printing point thereof.

19. In a printing machine, the combination with a projecting mechanism, of a positive film mechanism comprising a base member mounted for adjustment transversely of the path of the film, film guide members coacting with the edges of the film, one of said guide members being provided with a spring presed element engaging the film at the printing oint, a mask holder'having a mask opening t erein, a mask reversibly arran ed in said mask opening and provided witli a reducing element, a clamping member for said mask, and a light tube operatively associated with said projecting mechanism and mounted on said clamping member for adjustment.

20. In a printing machine, the combination with a projecting mechanism, of a positive film mechanism comprising a base member mounted for adjustment transversely of the path of the film, film guide members coacting with the edges of the film, one of said guide members being provided with a spring pressed element engaging the film at the printing point, a mask holder having a mask opening therein, and a mask reversibly arranged in said mask opening and provided with a reducing element.

21. In a printing machine, the combination with a projecting mechanism, of a positive film mechanism comprising film guide members coacting with the edges of the film, one of said guide members being provided with a spring pressed element engaging the film at the printing point, a mask holder having a mask opening therein, a mask reversibly arranged in said mask opening and provided with a reducing element, a clamping member for said mask, and a light tube operatively associated with said projecting mechanism and mounted on said clamping member for adjustment.

22. In a printing machine, the combination with a projecting mechanism, of a positive film mechanism comprising a base member mounted for adjustment transversely of the path of the film, a mask holder having a mask opening therein, a mask reversibly arran ed in said mask opening and provided witfi a removable reducing element, a clamping member for said mask, and a light tube operatively associated with said projecting mechanism and mounted on said clamping member for adjustment.

23. In a printing machine, the combination with aprojecting mechanism, of a positive film mechanism comprising a mask holder havin a mask opening therein, a mask reversib y arranged in said mask opening and provided with a removable reducing element, a clamping member for said mask and a light tube operatively associated with said projecting mechanism and mounted on said clamping member for adjustment.

24. In a printing machine, the combination with a projecting mechanism, of a positive film mechanism comprising a base member mounted for adjustment transversely-of the path of the film, a mask holder having a mask opening therein, and a mask reversibly arranged in said mask opening and provided with a removable reducing element.

25. In a printing machine, the combination with-a projecting mechanism, of a positive film mechanism comprising a supporting member mounted for adjustment transversely of the path of the film, a mask carried by said supporting member adjustable to vary the size of its opening and the position of its opening transversely of the film, a light tube operat vely associated with the mask, and

projecting mechanism mounted for adjustment transversely of the film.

26. In a printing machine, the combination with a projecting mechanism, of a positive film mechanism comprising a supporting member mounted for adjustment transversely of the path of the film, a mask carried by said supporting member adjustable to Vary the size of its opening and the position of its opening transversely of the film, and a light tube operatively associated with the mask.

In witness whereof I have hereunto set my hand.

, J AKOB BURKHARDT. 

